Electricity Energy Meters with prepaid balances are a solid idea because they allow you to refill them just like we do on our mobile phones. This project involves the use of Arduino and GSM modules to create an automated system. This system allows electricity balances to be recharged through SMS messages. If the system is unbalanced or low, it can stop the power supply to the house. And this system will automatically send users updates on their mobile devices, such as low balance alerts, cut off alerts, resume alerts, and recharge alerts, depending on the energy meter readings.

Using an Arduino and the power meter's calibration LED, we have interfaced the energy meter with Arduino. Our CAL LED only needs to be connected to an Arduino by means of an Optocoupler IC. Fig. Prototype of Energy Meter using GSM and Arduino

Arduino GSM Module 16x2 LCD Analogue Electricity Energy Meter Optocoupler 4n35 Resistors POT Connecting wires Bulb and holder SIM card Power supply Mobile Phone

As soon as the system comes on, it reads previous rupee values from EEPROM and restores them into variables; it compares the value with the predefined one and decides whether to proceed. Use relays to switch on the electricity of a house or office if the available amount is more than 15 rupees, for example. Once the balance falls below 15 rupees, Arduino sends a SMS to the phone of the user informing them of the low balance and asking them to recharge soon. The Arduino turns off the electricity supply of the home when the balance falls beneath 5 rupees and sends a SMS alerting the user of a 'Light Cut' and requesting him to recharge soon. Here you can find information on the GSM module and AT commands used to send and receive messages.

Now that our system can be recharged through our cell phones, we can do so simply by sending a SMS to it. We would send #45* if we want to recharge 45 dollars, here the # and * indicate the sum to be recharged. Upon receiving this message, the system extracts the recharge amount to update the system balance. In the video at the end, you will see how the system turns on the electricity in the house or office.

A schematic of the project circuit connections is shown; an Arduino UNO processor has been used to process all the components. Unit status and remaining balance are displayed on a liquid crystal display. LCD pins RS, EN, D4, D5, D6, D7 are connected to Arduino digital pin number 7, 6, 5, 4, 3, 2. GSM pins Rx and Tx are directly connected to Arduino pins Rx and Tx respectively. An adapter powered by 12 volts is used to power a GSM module. On pin 12 of Arduino, a relay is used to switch electricity through the ULN2003 relay driver.

An Analogue Electricity Energy Meter must first be purchased by the user. Once it has been opened, the user can locate the terminals of Pulse LEDs and Cal LEDs (cathode and anode). Once you have soldered two wires in each terminal, remove them from the meter and close it. Then tighten the screws. Now the LED's anode terminal must be connected to pin number 1

of the optocoupler. On an optocoupler, pin number two is connected to the cathode terminal, and pin number four should be directly connected to ground. In the pin number 5 of the optocoupler is an LED and Pull-up resistor. A similar terminal should be connected to Arduino pin 8 as well. The aim of this project is to gather information about the usage of energy by a specific consumer or user, using a wireless communications system (not requiring a visit to the consumer's home or office), and the system is called AMR (Automatic Meter Reading). AMR would involve remotely accumulating meter readings at a location through a wireless telecommunications system, instead of individuals visiting the site physically and taking notes.